package emailing

import (
	"bytes"
	"fmt"
	"html/template"

	"github.com/spf13/viper"
	gomail "gopkg.in/mail.v2"
)

type Mailer struct {
	TemplatesDir    string
	TemplatesConfig *viper.Viper
	SMTPConfig
}

type SMTPConfig struct {
	Host     string
	Port     int
	Username string
	Password string
}

func NewMailer(templates_dir string, tplcfg *viper.Viper, smtpconfig *viper.Viper) (*Mailer, error) {
	return &Mailer{
		TemplatesDir:    templates_dir,
		TemplatesConfig: tplcfg,
		SMTPConfig: SMTPConfig{
			Host:     smtpconfig.GetString("host"),
			Port:     smtpconfig.GetInt("port"),
			Username: smtpconfig.GetString("username"),
			Password: smtpconfig.GetString("password"),
		},
	}, nil
}

func (m *Mailer) Send(emailcfg string, to string, data any) error {
	cfg := m.TemplatesConfig.Sub(emailcfg)

	files := cfg.GetStringSlice("files")
	prefixed_files := []string{}
	for _, f := range files {
		prefixed_files = append(prefixed_files, m.TemplatesDir+f)
	}
	t := template.Must(template.ParseFiles(prefixed_files...))
	buf := new(bytes.Buffer)
	if err := t.ExecuteTemplate(buf, "main", data); err != nil {
		return err
	}
	body := buf.String()

	fmt.Println(body)

	message := gomail.NewMessage()

	message.SetHeader("From", m.SMTPConfig.Username)
	message.SetHeader("To", to)
	message.SetHeader("Subject", cfg.GetString("subject"))
	message.SetBody("text/html", body)

	d := gomail.NewDialer(m.SMTPConfig.Host, m.SMTPConfig.Port, m.SMTPConfig.Username, m.SMTPConfig.Password)
	if err := d.DialAndSend(message); err != nil {
		return err
	}

	return nil

}